Endless band for transmitting power



A g- 1 1942- A. KINDLIMANN ENDLESS BAND FOR TRANSMITTING POWER Filed Jan. 23, 1941 I I INVENTOR. HLBERT K/NDL /M/q/V/V ATTORNEY Patented Aug. 11, 1942 ENDLESS BAND FOR TRANSMITTING POWER Albert Kindlimann, Sils-Fex, Switzerland, as-

signor to Hevaloid Corporation, a corporation of Delaware Application January 23, 1941, Serial No. 375,565 Claims. (01. 74-232) The invention relates to endless bands for transmitting power, and more particularly, to endless transmission bands especially adapted for use in the driving of yarn spinning machines and the like.

It is well known that existing bands of the indicated type are either endless with no twist therein, or have a twist therein but in their initial state are not endless. Bands of the latter class, in many instances are specially woven on belt looms. These bands are cut transversely andsubsequently have the disconnected ends suitably joined together to make said bands endless; before the two ends are joined together the band is manipulated to form a twist therein.

In many instances the power transmitting bands are required to assume the twisted form referred to in order to properly function in the transmission of power. Such a twist very often is necessary only in one run of the transmitting band, this being particularly true in connection with yarn spinning machines and the like. The aforesaid twist in the normal transmitting band distorts the latter with consequent injury to the band. At the same time the overlapping or otherwise connected ends of the band have a ridge or other unevenness at the joint thereof which in the repeated travel of the band around the pulleys causes the band to produce a bump or thump and causes the development of strains or of other destructive forces which quickly result in deterioration or in breakage or which materially reduces the efficiency and useful life of the band.

Power transmitting bands and the associated pulleys, and particularly those used for yarn spinning machines, are frequently relatively narrow in width transversely and such bands, in practice, tend to slip sidewise from said pulleys with consequent interruptions of the power transmitting functions. Attempts have heretofore been made to overcome these objections by different means which however have created other objections whereby the efficiency and life of the bands is reduced. For instance the associated pulleys have been flanged or grooved or otherwise constructed in special ways to oppose the tendency of the transmitting bands to slip from said pulleys. With many types of the aforesaid special pulleys friction incidental to the operation of said pulleys by the bands, is developed to a high degree and heat is generated internally of said power transmitting bands to such an extent that the transmission efiiciency of the latter is quickly destroyed. Frequent replacement of the bands is accordingly required at relatively short intervals resulting not only in considerable waste in power transmitting bands but also a material reduction in the operative efiiciency of the mechanism with which such bands and pulleys are associated, because of the frequent interruptions due to band replacements.

The object of the invention is to provide an endless and unjointed power transmitting band constructed in a novel manner to include inherent characteristics whereby the objections enumerated above are overcome.

The invention contemplates primarily the provision of a power transmission band which is endless and unjointed and which includes an inherent longitudinal twist throughout a predetermined portion of its length.

Other objects and advantages of the invention will appear from the description hereinafter and the features of novelty will be pointed out in the claims.

In the accompanying drawing, which illustrates an example of the invention without defining its limits,

Fig. 1 is a perspective view of the novel power transmitting band in connection with conventional pulleys;

Fig. 2 is a perspective view of a tubular element illustrating a stage in the production of the novel power transmitting band;

Fig. 3 is a perspective view of the band illustrating another stage in the production thereof;

Fig. 4 is a fragmentary face view of a portion of said transmitting band;

Fig. 5 is a cross-section of the band on an enlarged scale taken on the line 55 of Fig. 4;

Fig. 6 is a distorted perspective cross-sectional view of the band at an intermediate stage of production, and

Fig. 7 is a similar distorted view of the band in its finished condition.

As shown, the novel power transmitting band consists of an endless unjointed web of material I0 folded inwardly upon itself at H and [2 in opposite directions preferably though not necessarily so as to overlap as illustrated at a in Figs. 5, 6, and 7, to form two plies I3 and I4 lying in surface engagement with each other. In the illustrated example the folds H and I2 of the web [0 are on the bias longitudinally thereof throughout a part of the length of said web It! and the corresponding overlapped portion a of the ply I3 or equivalent joint extends diagonally lengthwise of the band for a corresponding distance and in such case may continue in substantially parallel relation to the opposite edges of said band for instance in respective proximity thereto. A line of preferably zig-zag stitching I5 passes through the overlapped portion a or equivalent portions of the ply I3 and the ply Id, and follows the respective diagonal direction of said portion a and continuing straight directions of the remainder to secure the portion a in the desired overlapped condition and to fasten it or the equivalent portions of the ply I3 to the ply I 4. Additional lines of stitchings I6 are arranged lengthwise of the band in spaced parallel relation and pass through both plies I3 and I4 thereof to fasten the latter in place.

In its illustrated form the novel power transmitting band so far described is made of a suitable fabric as is generally the case with bands designed for use for instance in yarn spinning machines for operating the ring spindles thereof; it will be understood however that this is not intended to arbitrarily restrict the material which may be utilized in producing the trans mitting bands. That is to say, any fabric or other material comprising strong and flexible fibers including artificial or synthetic fibers, filaments, yarns, etc., etc., may be used, although at the present time cotton fabric is preferred in producing the novel band.

Any convenient method of manufacture which will produce the desired results may be utilized in the production of the novel power transmitting bands. In the preferred method of manufacture, the initial step comprises the production of a textile tube IT as shown in Fig. 2 for instance by weaving the same on looms such as are customarily used in industry for such work. The textile tube I! may be of any diameter and length both dependent upon the dimensions and type of transmitting bands to be produced therefrom, and in any case is woven in a manner consistent with the type of service for which bands produced therefrom are designed.

Subsequently to its completion the textile tube I1 is cut, for instance on the lines I8 into a plurality of individual sections I9 each of which is endless and unjointed. The individual width of the sections I9 is determined by the width of the ultimate bands, and generally is approximately twice that of the latter or, if the overlap a is to be included therein is somewhat more than twice as wide as the transmitting bands to be produced therefrom. The length of the bands in any case corresponds to the diametric dimensions of the tube I! which are always determined by the bands for which the textile tube I! is designed.

After a section I9 has been cut from the tube [1, the opposite edge portions thereof are folded inwardly toward each other for instance into overlapping relation as shown in distorted form in Fig. 6. The inward folds are on the bias with respect to the length of the section I9 and may continue entirely around the band. In the event that the bias folds extend over only a part of the band, said folds throughout the remainder of the latter may be straight and in parallel relation to each other. As a result of this procedure the overlapped portion a of the band extends diagonally of the band in a lengthwise direction either completely around the band or throughout only a part thereof, and in the latter case may continue in a straight line which for convenience may be located in contiguous relation to the opposite folded edges of the band which are parallel to each other as shown in Fig. 4.

At this stage the section I9 has been folded into the form of a band of the width desired and consisting of the plies I3 and I 4, the former including the overlapped portion a. The latter is then fastened in place and connected with the ply I4 by the zig-zag stitching I5 as illustrated in the distorted view in Fig. 7, said stitching I5 throughout the diagonal part of the overlapped portion a being correspondingly diagonal and otherwise being straight and in parallel proximity to the opposite folded edges I2 of the band. The lines of stitches I6 which extend in spaced parallel relation to each other and to the folded edges of the band are then added to securely fasten the plies I3 and I4 in surface engagement with each other as illustrated in distorted form in Fig. 7.

With this construction the novel power transmitting band is endless and unjointed and when under operative tension in use includes an inherent logitudinal twist b for instance as shown in Fig. l. The twist b corresponds in extent to the diagonal portion of the overlap a and in the illustrated example is located in the one run of the band when the latter is functioning to transmit power for instance from one pulley 20 to a second pulley 2I.

This inherent twist b enables the band to function efficiently in connection with pulleys arranged transversely to each other, and also efliciently opposes any tendency of the band to slip from the relatively narrow pulleys 20 and 2|. Because of the fact that the aforesaid twist constitutes an inherent characteristic of the band, the latter will at no time be subjected to excessive strains as is the case when a conventional power transmitting band is twisted for any operative reason.

The diagonal portion of the overlap a and the corresponding portion of the stitching I 5 may extend throughout the band to varying extent dependent upon the type of inherent twist b which is desired. It will be understood that the twist b will automatically develop as a result of the pull upon the diagonally extending portion of the transmitting band whenever the latter is under operating tension.

Although the present invention has been described in conjunction with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention, as those skilled in the art will readily understand. Thus it will be observed that instead of having the inwardly folded portions of the endless unjointed web of material overlap each other, the opposed edges of said inwardly folded portions may abut to form a butt joint. It is to be further observed that the bias folds of said inwardly folded portions may continue around the entire band and that the diagonal joint of the inwardly folded portions, either overlapping or butt joint, may correspondingly extend throughout the entire band. Such variations and modifications are considered to be within the purview and scope of the claims.

I claim:

1. A power transmitting band comprising an endless web consisting of a plurality of plies connected with each other along substantially parallel lines longitudinally of their longitudinal edges and united in bias surface contact with each other relatively to said connected edges whereby said band under operative tension will develop a lengthwise twist throughout a predetermined part of its length and whereby said twist remains between two pulleys on which said band is mounted.

2. A power transmitting band comprising an endless web folded upon itself lengthwise to provide a plurality of plies in surface engagement with each other, said folding being on the bias longitudinally of the Web to form a diagonal joint lengthwise thereof whereby said band under operative tension develops a lengthwise twist throughout its length.

3. A power transmitting band comprising an endless web folded upon itself lengthwise in opposite directions to provide a plurality of plies in surface engagement with each other, said folding being on the bias longitudinally of the web whereby said band under operative tension develops a lengthwise twist of predetermined extent, and means for maintaining the web in its folded condition.

4. A power transmitting band comprising an endless web folded upon itself lengthwise in opposite directions in overlapped relation to provide two plies in surface engagement with each other, said folding being on the bias longitudinally of the web to form a diagonal joint lengthwise thereof whereby said band under operative tension develops a lengthwise twist of predetermined extent, and stitching for maintaining the web in its overlapped folded condition.

5. A power transmitting band comprising an endless web, folded upon itself lengthwise in opposite directions in overlapped relation to provide a plurality of plies in surface engagement with each other, said folding in part being on the bias longitudinally of the web to form a diagonal joint lengthwise thereof whereby said band under operative tension develops a lengthwise twist of predetermined extent, a line of zigzag stitches following the diagonal joint and passing through the contiguous folded portions of the web and through the contiguous ply to fasten the associated folded portions in place and to said contiguous ply, and additional lines of stitchings in spaced parallel relation lengthwise of the band extending through the plies to secure the same in said folded relation.

ALBERT KINDLIMANN. 

